DAVID HALBERSTAM, who has died aged 73, was a controversial American correspondent and author, always suspicious of the official version of events during the Vietnam war, and regularly at odds with US Army brass, the Saigon authorities, Washington officials and, on occasion, his employers.
As a reporter for the New York Times Halberstam criticised what was, in his view, the false optimism in both capitals and the atmosphere of cynicism and conspiracy he detected in the Vietnamese leadership. On the job he was brave, energetic and diligent. His critics found him something of a crusader.
His Vietnam assignment, in 1962 and 1963, before the major American military commitment, came at a time when many journalists were profoundly sceptical of both the words and actions of American "advisers" in Saigon and the Vietnamese leaders.
Their assertions that the war was going well, and America's insistence that it would "sink or swim with Diem", struck Halberstam and other correspondents on the spot as way off the mark. Diem, in fact, was overthrown in a military coup late in 1963.
Halberstam was perhaps the first man from a major newspaper to report what he saw as a clearly deteriorating military situation. The reputation of his paper gave authority to his dispatches in the higher echelons of government, where the New York Times is required reading.
So furious were both State Department and White House with Halberstam's assessment of the situation that President Kennedy tried to get the paper to replace him. But the Times, which had been critical on its editorial page about Washington's policy in Vietnam, withstood presidential pressure and Halberstam remained on the assignment for 15 months.
Madame Nhu, wife of Ngo Dinh Diem's brother, who was chief of secret police, managed to give Halberstam's reports, and the reporter himself, special attention. After remarking that she was delighted every time a monk set himself on fire, she added that Halberstam should also be barbecued, saying: "I will gladly supply the fluid and the match."
Though he remained as correspondent in Saigon for more than a year, there were moments when some editors in New York feared his dispatches might lead to charges that the paper was soft on the Communists. But after that difficult period, as much of what he and other critics of American policy had written turned out to be correct, he was awarded, in 1964, a Pulitzer Prize, the most valued honour in American journalism, for his work in Vietnam.
Harper's magazine called him "at 35, a legend in American journalism". In a University of California poll 150 intellectuals called him and Bernard Fall the most important influences on their thinking on Vietnam.
David Halberstam was born on April 10 1934 in New York City and graduated from Harvard, where he was managing editor of The Crimson. He worked for the Nashville Tennessean before joining the New York Times in 1960. The following year he was sent to the Congo, where he and his editors discovered he was the kind of reporter who did his best work when left free to roam, following his instincts, choosing his own assignments.
After the Vietnam interlude the Times assigned him to Poland in 1965, while worrying that he might be too soft in his reporting, for fear of being expelled like his Times predecessor AM Rosenthal. In the event Halberstam was indeed told to leave at the end of the year for "writing slanderous and offensive articles". "I was not at all that surprised," he remarked.
Back in New York he left the paper and for four years was a contributing editor of Harper's before becoming a fellow of the Adlai Stevenson Institute and devoting his time to writing books.
His first major book, in 1965, was The Making of a Quagmire, a prophetic work on the American commitment in Asia. There followed The Unfinished Odyssey of Robert Kennedy (1968) and Ho (1971), the story of the North Vietnamese leader.
Perhaps Halberstam's most notable book was The Best And The Brightest (1972), an account of the 1960s, of the Kennedys and Lyndon Johnson and the advisers they brought into government to help run the war. He found these appointed figures overconfident, arrogant even, making questionable decisions and misleading the country. He was critical of their lack of accountability.
The Powers That Be was an equally exhaustive account of the relationship of radio, television and newspapers to the making of policy and the making of presidents, and an analysis of the families who controlled those media. He also published a novel, One Very Hot Day (1967), predictably about a patrol by a Vietnamese unit led by American officers.
Although Halberstam and his Vietnamese colleagues were widely criticised at the time in Washington and by the brass in Saigon for the pessimistic tone of their reports, an American Army study 14 years after Saigon fell found the press had not been responsible for the loss of South Vietnam.
The Army's Centre of Military History concluded that it was the lack of a winning strategy and mounting American casualities, rather than news reports, which had nourished the anti-war movement and led Washington to pull out.
In the wake of 9/11 Halberstam wrote Firehouse (2002), a highly-praised and perceptive book about the attack on the Twin Towers, following the fire crew of Engine 40, Ladder 35.
David Halberstam, who was killed in a car crash in California on Monday, is survived by his wife and daughter. In 1980 his brother Michael, a cardiologist, was murdered by an armed escaped convict who broke into his home.